Help please

Interpreting a short passage of the text to identify the best class candidates as well as the inheritance, composition or aggregation relationships that might exist among them:
Assume that a simple batch payroll system consist of the employees in the XYZ Company, and their associated data, such as Employee ID, name / last name, and birthday. Also Employee should belong to one of the department – Department of Sales or Department of Advertisement, and employees could belong to the union. Employees belong to the union must pay union charge as 0.1% from monthly income. Some employees are paid only by a flat salary (monthly rate), some are paid ONLY an hourly rate (weekly hourly rate), and some are paid only on a commission based on their sales (usually % from their monthly sales).

Help please

Interpreting a short passage of the text to identify the best class candidates as well as the inheritance, composition or aggregation relationships that might exist among them:
Assume that someone has defined Course as an entity with attributes name, dept, year, semester (with values F – “Fall”, S- “Summer”, W- “Winter”).
Also each course is associated with:
- course description (a paragraph of text),
- name of professor and his office number, and a phone extension (note that one instructor could teach several courses, one course could teach only one instructor).
- student enrollment list for the course(usually up to 30 students),
- average course student mark (average of all students from student enrollment list)